Interpretive Summary: The taxonomic identity of the western cavity-nesting bee Osmia aglaia was confounded with that of another species in the 1950’s. Because the bee is being developed as a manageable pollinator for bramble fruits on the West Coast, its identity required clarification. The species is shown to be distinctive and valid, with a geographic range restricted to California and Oregon.

Technical Abstract:
The identity of the western US bee Osmia aglaia Sandhouse is resurrected from synonymy with O. laeta Sandhouse. Distinguishing morphological characters are provided that justify the species status of O. aglaia. The species’ geographic range is restricted to California and Oregon western of the Sierra-Cascade Crest.